"Fixup too large" error with -fasm on PowerPC

The native code generator on PowerPC can sometimes generate code that doesn't pass the assembler. The error is "Fixup too large" from the assembler.

Workaround is to use -fvia-C.

Wolfgang Thaller says this: Conditional branches on the PowerPC only have 16 bits for the displacement. I have been reluctant to fix this so far because it means either slowing down all conditional branches or actually checking the size of the generated code before deciding what branch instructions to use, which I'm afraid would add an additional pass to the NCG.